[core] introduce the method to wake system up
When using aggressive power management on devices like mobile or laptop devices, There's generally one objective, saving as much as power as possible. To do this on some devices we keep system in deep sleep/suspend for most of the time.
This means userspace will be frozen as well. For most part this is fine, but for services like push notification helper, or update manager or for example alarm application, this is not acceptable and it would mean that we need to wake system at some point.
This helpers on org.kde.Solid.PowerManagement are supposed to help with that.
You have two possibilities,
- Wake system instantly: this is useful when screen is turned off, but device is not in sleep, and you want to show e.g notifications on screen.
- Wake system in future: You want to schedule alarm or for example wakeup 15 mins later to check for notifications.
Once system is awake, powerdevil will ping dbus service of your choice and call the method "wakeup", if you send a dbus reply with true with first argument, powerdevil will simulate user activity and wake system fully or otherwise it will let you do your work in background and will not disturb user.
Related: #2